1. Field of the Invention
This invention relates to a closed, but vented, receptacle constructed of good heat transfer material and partially filled (approximately one-third) with a eutectic solution. The upper portion of the interior of the receptacle includes CO.sub.2 spray head structure for forming CO.sub.2 snow therein and which may fall down upon the surface of the eutectic solution and the lower portion of the interior of the receptacle includes structure for pressure jet discharge of liquid CO.sub.2 thereinto adjacent the bottom of the receptacle, the liquid CO.sub.2 flow capacity of the pressure jet discharge structure and the lower portion of the interior of the receptacle being appreciably more than the liquid CO.sub.2 flow capacity of the CO.sub.2 spray head structure and the jet discharge structure being arranged to effect a circulatory movement of the solution within the tank including generally opposite longitudinal and generally opposite vertical improvements of movement.
2. Description of Related Art
Many enclosed containers heretofore have been provided into which liquid CO.sub.2 may be spray discharged for forming CO.sub.2 snow within the containers. In addition, cooling containers for chilled eutectic solutions also have been provided as well as cooling containers having transfer passages formed therein. However, the cold tank of the instant invention provides a closed container (but having its upper portion vented to the exterior) to be partially filled with a eutectic solution and into whose upper portion liquid CO.sub.2 may be spray discharged for forming snow within the receptacle upper portion, the snow falling down within the receptacle onto the surface of the eutectic solution. Further, the container also includes spray jet discharge structure within a lower portion thereof below the surface of the eutectic solution through which an appreciably larger quantity of liquid CO.sub.2 may be discharged into the eutectic solution, the spray discharge of liquid CO.sub.2 into the eutectic solution being rapidly transformed into CO.sub.2 snow for suspension in and chilling the eutectic solution as well as a small quantity of CO.sub.2 gas which may rise through the eutectic solution to the surface thereof.
The injection of liquid CO.sub.2 into the eutectic solution causes sufficient circulation of the eutectic solution within the lower portion of the receptacle to cause the snow falling to the surface of the solution to be blended therein, thereby more rapidly chilling the eutectic solution down to a point elevated only slightly above its freezing point.
By this method, the heat absorbing capacity of a given amount of liquid CO.sub.2 is increased over presently known and used methods of chilling a cold tank or the like.